From early in fetal life to possibly beyond the teenage years, human bones continue to ossify or grow. Depending on the architecture of a bone, ossification occurs at various locations on the bone and at various times during the maturation of the bone. A femur, for example, may ossify from five different centers. Furthermore, an epiphysis or a location of bone growth of a distal femoral extremity may not unite with the bone, thus finishing the bone growth, until or beyond an age of twenty-years old. Unfortunately, myriad medical conditions may require removal of a distal femoral extremity or other portions of the bone resulting in possible removal of an epiphysis or a growth plate. Patients that require such a medical procedure require a device to maintain the proper length of the bone due to the loss of the growth plate.
Prior implementation of expandable implants required constant monitoring of bone growth and further may have required invasive techniques to affect expansion of the implant. Monitoring bone growth requires repeated interaction with the patient and continual analysis of the bone growth rate and amount. While necessary, constant monitoring may be inconvenient. In addition, the expandable implant requires a certain rate of expansion to maintain the length of the implant approximately equal to other bones and this expansion may require invasive techniques. In lieu, of invasive techniques, portions of the expandable implant may remain accessible for external adjustment. Other possibilities for expansion include exterior devices to affect the change in extension length. Such examples of exterior devices include remote control electrical power extension or magnetic effectuation of expansion.
Remote expanding devices or adjustments with external portions of the expandable implants present myriad difficulties. The chance of infection remains possible with maintenance of any opening into the body in a situation where a portion of implant is externally accessible. When remote devices are used, the possibility exists for inopportune or unwanted expansion of the implant. In addition, the possibility exists that the ability to remotely expand the implant will be completely lost. As such, there remains a need in the art for a non-invasive expandable implant that does not require remote effectuation of expansion. In addition, there is a need in the art for the rate of expansion of the expandable implant to match the corresponding bones for example the left or right femur.